package org.apache.lucene.search.spans;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import org.apache.lucene.util.ToStringUtils;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Set;

/** Matches spans containing a term. */
public class SpanTermQuery extends SpanQuery {
	protected Term term;

	/** Construct a SpanTermQuery matching the named term's spans. */
	public SpanTermQuery(Term term) {
		this.term = term;
	}

	/** Return the term whose spans are matched. */
	public Term getTerm() {
		return term;
	}

	public String getField() {
		return term.field();
	}

	/**
	 * Returns a collection of all terms matched by this query.
	 * 
	 * @deprecated use extractTerms instead
	 * @see #extractTerms(Set)
	 */
	public Collection getTerms() {
		Collection terms = new ArrayList();
		terms.add(term);
		return terms;
	}

	public void extractTerms(Set terms) {
		terms.add(term);
	}

	public String toString(String field) {
		StringBuffer buffer = new StringBuffer();
		if (term.field().equals(field))
			buffer.append(term.text());
		else
			buffer.append(term.toString());
		buffer.append(ToStringUtils.boost(getBoost()));
		return buffer.toString();
	}

	/** Returns true iff <code>o</code> is equal to this. */
	public boolean equals(Object o) {
		if (!(o instanceof SpanTermQuery))
			return false;
		SpanTermQuery other = (SpanTermQuery) o;
		return (this.getBoost() == other.getBoost())
				&& this.term.equals(other.term);
	}

	/** Returns a hash code value for this object. */
	public int hashCode() {
		return Float.floatToIntBits(getBoost()) ^ term.hashCode() ^ 0xD23FE494;
	}

	public Spans getSpans(final IndexReader reader) throws IOException {
		return new TermSpans(reader.termPositions(term), term);
	}

}
